Disk array apparatus

• US 6,223,300 B1
• Filed: 10/29/1998
• Issued: 04/24/2001
• Est. Priority Date: 11/21/1997
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Gotoh, Mitsuo
• Primary Examiner(s): Iqbal, Nadeem
• Application Number:
  US09/182,373
• Time in Patent Office: 908 Days
• Field of Search: 714/5, 714/6, 714/7, 714/13, 714/15, 714/20, 714/25, 714/39, 714/42, 714/47, 714/723, 714/763, 714/770, 711/114, 711/115, 711/100, 711/133, 711/173
• US Class Current: 714/5.1
• CPC Class Codes: G06F 11/3433 for load management allocation of a server based on load conditions G06F9/505; load rebalancing G06F9/5083; redistributing the load in a network by a load balancer H04L67/1029
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 2201/88 Monitoring involving counting
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A disk array apparatus is provided which, without stopping its host system, reconstructs data areas of its configured storage devices by determining optimum array parameters in keeping with disk access trends. Each of the storage devices includes a data area furnished in units of a stripe size, a log storage area for storing access logs, and a work area in which to change the data area. The inventive apparatus comprises: an access log storing means for storing access logs to the log storage areas; an access log analyzing means for analyzing trends of access to the storage devices based on the access logs; an array parameter judging and changing means for judging the validity of array parameters based on the result of the analyses and for setting optimum array parameters anew as needed; and a reconstructing means for reconstructing the data areas as per the changed array parameters.

Claims

1. A disk array apparatus comprising:

a plurality of storage devices accessed in parallel by said disk array apparatus, each of said storage devices including a data area established beforehand in units of a stripe size, a log storage area for accommodating logs of access to said storage devices, and a work area in which changing operation of said data area of said storage devices is carried out;

access log storing means for storing the access logs to said log storage areas;

access log analyzing means for analyzing trends of access to each of said storage devices on the basis of said access logs;

array parameter judging and changing means for judging whether existing array parameters are valid on the basis of results of analysis from said access log analyzing means, said array parameter judging and changing means further establishing optimum array parameters to replace said existing array parameters if said existing array parameters are judged invalid; and

reconstructing means for reconstructing said data area of each of said storage devices in accordance with said optimum array parameters established by said array parameter judging and changing means.

2. A disk array apparatus according to claim 1, wherein, if said array parameter judging and changing means judges it necessary to enlarge said stripe size as one of said array parameters, said reconstructing means causes stored data to be copied from said data area into said work area in units of a new stripe size in each of said storage devices, said reconstructing means further generating new parity based on said new stripe size in said work area before copying said stored data from said work area back to the original data area, whereby said data area is reconstructed in each of said storage devices.

3. A disk array apparatus according to claim 1, wherein, if said array parameter judging and changing means judges it necessary to reduce said stripe size as one of said array parameters, said reconstructing means causes stored data to be copied from said data area into said work area in units of the old stripe size in each of said storage devices, said reconstructing means further generating new parity based on a new stripe size in said work area before copying said stored data from said work area back to the original data area, whereby said data area is reconstructed in each of said storage devices.

4. A disk array apparatus according to claim 1, wherein said log storage area and said work area are provided in one region in each of said storage devices.